Method:1. Soak the black gram and green gram in water for 3 hours.2. Drain water.3. Grind smoothly to a idli batter consistency.4. Add salt, pepper powder, cumin powder, coriander leaves and ginger.5. Mix them thoroughly.6. Prepare idly by pouring the batter in idli plates and steam them in a cooker.7. Serve with coconut chutney or onion chutney and sambar